Slide holder for an automated slide loader

ABSTRACT

A slide holder ( 6 ) for use with a microscope to accurately locate a slide ( 19 ) in position under the microscope has a pivotal lever ( 13 ) having a clamping and locating portion ( 14 ) with abutments ( 15 ) and ( 16 ) which bear on respective edges of the slide when it is in the clamped position. Further abutments ( 10 ) on a fixed angular plate ( 9 ) locate the other edges of the slide. The slide holder is adapted for mounting on a slide translation stage of a slide loader ( 1 ) which includes a stationary sensor block ( 20 ) positioned to engage the lever ( 13 ) when the slide holder moves from its inspection or scanning position under the microscope to a loading/unloading position. The slide translation stage includes a robotic head for lifting and depositing slides and the translation stage includes a bar code reader to read a bar code on the slide.

FIELD OF THE INVENTION

This invention relates to slide holders for use with an automated slideloader.

BACKGROUND OF THE INVENTION

In recent years there has been a rapid growth in the reported use ofautomated image processing systems to analyse images obtained from videoand digital cameras mounted on optical microscopes. However, thebenefits of using such systems have been offset by the need to manuallyload and unload microscope slides on the microscope.

There is no stand-alone automated slide loader in the market that loadsand unloads slides to and from an external, free-standing opticalmicroscope. Current processes of loading and unloading slides are eitherperformed manually or require a dedicated instrument that already has abuilt-in microscope and imaging system.

There are several patents that describe systems to automatically loadand unload slides onto microscopes including U.S. Pat. No. 4,248,498(Georges), and U.S. Pat. No. 4,501,495 (Faulkner). These patentsdescribe systems whereby the slide loader is integrated into amicroscope/imaging platform. It is not possible with these designs tointerface to free-standing microscopes.

Slide holders on current model microscopes typically consist of a springloaded pivot arm to position and clamp slides onto the slide holder. Oneform of slide holder disclosed is U.S. Pat. 4,159,875 (Hauser). Theshortcomings of such holders include:

a) they are limited to manual operation only. They require the user tomanually open the clamping mechanism, accurately position the slide onthe slide holder, and then release the clamping mechanism. Consequently,such methods are not suited to automated scanning systems as theyrequire constant attendance from laboratory staff to load and unloadslides.

b) the positional accuracy achieved by manually locating slides is notalways guaranteed.

The use of vacuum chucks as an alternative means to clamp slides onmicroscope stages have been described in U.S. Pat. No. 4,508,435(Graham) and U.S. Pat. No. 4,981,345 (Berry). These chucks canaccommodate X and Y motion of the stage by the use of flexible vacuumconnections but have the following shortcomings:

a) positional accuracy of the slide under the microscope is notguaranteed either by manual or robotic positioning;

b) considerable modifications to a microscope stage are required toaccommodate vacuum lines (a vacuum pump is also required but can bemounted away from the microscope).

c) to obtain adequate clamping (suction) of a slide, both ends of theslide would require vacuum thereby reducing the effective scan area onthe slides. Therefore critical features on the slide may be missed.

d) Vacuum chucks and associated plumbing can obstruct the optical pathbetween a microscope's condenser and objective lens.

U.S. Pat. No. 4,012,111 describes a slide holder that requires the userto position the slide by hand and push to clamp the slide down. Itclaims to be able to position slides accurately and repeatedly. Theshortcomings of this holder are:

a) the slide holder can only be used manually as it request the user tomanually place the slide against one slide retainer before the slidecould be clamped down.

b) the slide holder requires a user to use two hands to position a slidecorrectly; one hand to hold the slide against the fixed locaters on theback and the slide retainer, and the other hand to clamp the slide. Itis not designed to automatically locate the slide.

c) the positional accuracy in the x-y plane is dependent on humanplacement of the slide.

d) the positive force required to clamp the slide into position may leadto crack and chipping of slides.

SUMMARY OF THE INVENTION AND OBJECT

It is an object of the present invention to provide a slide holder foruse with an automated slide loader for a microscope in which the shortcomings of the known slide holders and slide loaders are ameliorated.

The invention thus provides a slide holder for use with a microscope,characterised in that said holder comprises a slide receiving regionhaving a plurality of fixed slide locaters, a slide locating andclamping means movably mounted on the slide holder and including afurther plurality of slide locaters for engaging the slide and moving itinto positive engagement with the fixed locaters whereby the slide isaccurately located and clamped in a fixed position on the holder.

By using the defined combination of fixed locaters and movable locatingand clamping means, the slide does not need to be initially placed onthe slide holder with any great accuracy since movement of the locatingand clamping means ensures that the slide is always accuratelypositioned against the fixed locaters as the slide is clamped.

The fixed locaters and the locaters on the slide locating and clampingmeans preferably engage only the edge regions, and preferably only theedges, of the slide to thereby maximise the scan area capable of beingviewed by the microscope during examination of each slide.

In a preferred form of the invention, the movable locating and clampingmeans includes an arm pivoted to the slide holder for movement betweenan open slide loading position and a closed slide locating and clampingposition, said arm preferably having an extended lever portion which maybe manually or mechanically engaged to move the arm to the openposition, and biasing means for moving the arm to the locating andclamping position when the lever means is released.

The slide holder is preferably configured to be supported by a motorisedtranslation stage associated with a microscope. Such motorisedtranslation stages are known in the art and operate to move the slideholder from a load/unload position to a microscope viewing position inwhich the slide is appropriately positioned under the microscope. Insuch an arrangement, the lever means defined above is positioned toengage a stationary sensor block to pivot the arm from the locating andclamped position to the open position as the motorised translation stagemoves towards the load/unload position.

It will be appreciated from the above that the slide holder lends itselffor use with an automated slide loader adapted to lift slides from aslide tray and deposit the slides onto the slide holder when it is inits load/unload position and the clamping and locating arm is open.

In a further aspect the invention provides a slide holder adapted formounting on the slide translation stage of a microscope, said slideholder having a slide clamping and/or locating means having an open orloading position and a closed position, and means for moving theclamping/locating means from one position to the other as the slideholder is moved by the translation stage to and from the loadingposition.

This facility enables the microscope to be used with an automated slideloader, such as that defined further below.

In another aspect, the invention provides a slide loader for use with amicroscope fitted with a motorised translation stage, including transfermeans for lifting slides from a slide tray or the like, slide holdermeans adapted for mounting on said motorised translation stage formovement from a slide loading/unloading position to a slide inspectionor scanning position under said microscope, said transfer means beingadapted to position the lifted slide on the slide holder means, and tolift the slide from the slide holder means after inspection/scanning,said slide holder means including means operative to clamp a slidepositioned on the slide holder means during movement of the translationstage from the loading/unloading position to the inspection/scanningposition, and for releasing the clamping means when the slide holderreturns to the loading/unloading position.

In a preferred form of the invention, the slide holder means is asdefined in relation to the first aspect of the invention, the slideloader preferably including means for engaging the lever means as theslide holder is moved by the translation stage towards theloading/unloading position.

The transfer means of the slide loader preferably includes a robotichead member including means for lifting and depositing slides, saidtransfer means being mounted for independent horizontal and verticalmovement during slide transfer from a slide tray or the like to theslide holder.

The slide loader preferably includes a bar code reader adapted to read abar code applied to said slide thereby enabling the slide loader systemto identify and track the slide to be inspected.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be more readily understood, a preferredembodiment of each of the above aspects of the invention will now bedescribed with reference to the accompanying drawings in which:

FIG. 1 is a perspective view of a slide loader embodying the inventionpositioned adjacent a microscope arrangement incorporating a motorisedtranslation stage;

FIG. 2 is a schematic perspective view, on an enlarged scale, of theslide loader and slide holder embodying the invention showing theessential components thereof and an opening for the microscope assembly;

FIG. 3 is a perspective view of the slide holder embodying theinvention;

FIG. 4 is similar to FIG. 3 but shows a slide in position on the slideholder; and

FIG. 5 is an enlarged perspective view of a spring locating component ofthe slide holder of FIGS. 3 and 4.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring firstly to FIGS. 1 and 2 of the drawings, the slide loader 1includes a housing 2 within which a multiplicity of slide supportingtrays 3 are located in a vertical stack. A slide transfer means 4 (FIG.2) includes a robot head 5 incorporating a suction cup (not shown) withan associated vacuum supply which enables automated lifting of slides 19from a selected tray 3 followed by depositing of the slides on a slideloader 6 carried by a motorised translation stage of a microscopeassembly M. The transfer means 4 is mounted within the slide loader 1for independent horizontal and vertical movement which enables the robothead to be automatically moved in response to a command from an externalcontroller (not shown) to select a designated slide from one of thetrays 3 for loading onto the slide holder 6. An arm 18 supporting therobot head 5 also supports a barcode reader B which operates to read abarcode area b on each slide as it is picked up and returned to the tray3 by the robot head 5 to ensure that the slides are appropriatelymonitored and validated.

Referring now to FIGS. 3, 4 and 5 of the drawings, the slide holder 6includes a frame 7 including a slide location region 8 surrounded on twosides by a shaped angular plate 9 incorporating three fixed slidelocating abutments 10. A pivotable arm 11 is mounted on the slide holderframe 7 by a pivot pin 12 engaging the frame 7. The arm 11 has anextended lever portion 13 and a clamping portion 14 having slideengaging abutments 15 and 16, the abutment 15 forming part of adeformable spring component 17, as illustrated in FIG. 5 of thedrawings, by means of which the slide holder can compensate for slidesof varying sizes. The locating and clamping arm 11 has an associatedbiasing means (not shown) by means of which the arm is biased towardsthe closed position, as illustrated in FIGS. 3 and 4, whenever the lever13 is not held in the open position ready for a slide to be dropped ontothe holder 6.

Referring again to FIGS. 1 and 2 of the drawings, it will be noted thatthe slide loader 1 includes a stationary sensor block 20 positioned toengage the lever 13 of the slide holder 6 when the motorised translationstage of the microscope M moves the slide holder 6 from its inspectionor scanning position under the microscope M to the loading/unloadingposition. This engagement pivots the arm 11 and moves the clamping andlocating portion 14 to the open position to enable an existing slide tobe removed or a new slide to be deposited. As soon as the translationstage moves towards the inspection position under the microscope, thelever 13 is released and the arm 11 is biased to the locating andclamping position with the slide located and clamped by the abutments10, 15 and 16, as illustrated in FIG. 3.

It will be appreciated that the slide holder 6 is able to be usedmanually with the operator moving the lever 13 by hand. When the lever13 is released, it operates to locate and clamp the slide 19 in therequired position whereby the need for manual positioning of the slide,other than rough positioning on the slide holder, is not required.

The above described slide holder has a number of important advantages,including the following:

1. The slide holder is designed to permit gross misalignment of a slideas it is positioned on the slide holder by the transfer mechanism.

2. The slide holder operates to position the slide accurately andrepetitively, which enables a particular slide to be re-scanned tolocate important features at a future time.

3. When the slide holder is operated in the automatic mode, thepossibility of slide damage occurring during positioning and clamping ofthe slide in the slide holder is minimised by the slow movement of theclamping device which is determined by the speed of the motorisedtranslation stage, as well as by the cushioning effect of the spring 17.

4. The slide holder can be used as a stand-alone slide holder for manualslide loading, as well as part of an automatic slide loading mechanism.

5. The slide holder provides a single mechanism designed to perform boththe slide positioning and clamping operations.

The slide loader is a stand alone system which does not require anin-built microscope, and is capable of loading and unloading slides froma number of different optical microscopes equipped with motorisedtranslation stages.

1. An automated microscope slide loading apparatus comprising: a slideholder comprising slide clamping and locating means including a clampingarm with slide engaging abutments and having an open position forloading and unloading a slide and a closed position for clamping a slideinto a fixed position on the holder for inspection or scanning by amicroscope wherein, the clamping and locating means further comprisesengagement means remote from the clamping arm for engagement with aslide loader such that the clamping arm is moved from the closedposition to the open position during movement of the slide holder awayfrom an inspection or scanning position of the slide holder under amicroscope to a slide loading and unloading position of the slide holderat a distance from the microscope.
 2. An automated microscope slideloading apparatus as defined in claim 1, wherein the slide loaderfurther comprises a housing for a plurality of slide supporting trays;and transfer means for automated transfer of slides to and from aselected tray and the slide holder.
 3. An automated microscope slideloading apparatus as defined in claim 2, wherein the transfer means ismounted within the slide loader for independent horizontal and verticalmovements during slide transfer to and from the selected tray and theslide holder.
 4. An automated microscope slide loading apparatus asdefined in claim 3, wherein the transfer means includes a robot headmoved in response to a command for enabling automated lifting of slidesfrom the selected tray and depositing of slides on the slide holder. 5.An automated microscope slide loading apparatus as defined in claim 2wherein the transfer means includes a barcode reader for reading a barcode applied in relation to each of the slides thereby enabling theslide loader to identify and track slides to ensure that the slides aremonitored and validated as they are transferred to and from a selectedtray and slide holder.
 6. An automated microscope slide loadingapparatus as defined in claim 5, wherein the transfer means includes arobot head moved in response to a command for enabling automated liftingof slides from the selected tray and depositing of slides on the slideholder, and wherein the barcode reader is supported by and moves withthe robot head.